1. Field of the Invention
This invention relates to a ceramic circuit board, more particularly to a ceramic circuit board including a heat-dissipating unit and to a method of making the same.
2. Description of the Related Art
Normally, a conventional ceramic circuit board is a ceramic-copper plate that is formed by eutectic-bonding a ceramic substrate made of, e.g., Al2O3, AlN, TiO2, ZrO2, ZnO, 2MgO.SiO2, or BaTiO3, and copper foils using direct copper bonding (DCB). The ceramic substrate has electrical insulating ability, thereby being able to insulate a plurality of electronic components disposed on the conventional ceramic circuit board.
Referring to FIG. 1, a conventional ceramic circuit board 1 is shown, and a method of making the same includes (A) providing a ceramic substrate 10, and first and second copper foils 11,12, (B) eutectic-bonding the first and second copper foils 11,12 respectively to top and bottom surfaces of the ceramic substrate 10, and (C) patterning the first copper foil 11 to form two spaced apart conducting portions 111.
Referring to FIG. 2, the ceramic circuit board 1 is used for packaging an electronic component such as a horizontally structured light emitting diode (LED) 91. Generally, the ceramic substrate 10 is formed by virtue of a conventional ceramic-making process (e.g., tape casting, slip casting, or pressing). However, the ceramic substrate 10 made by the conventional ceramic-making process has a thickness larger than 0.2 mm such that the ceramic substrate 10 is too thick for the horizontally structured LED 91 in terms of heat-dissipation. The ceramic substrate 10 is unable to efficiently transfer heat generated by the horizontally structured LED 91, thereby reducing the service life of the electronic component and adversely affecting the efficiency of the electronic component.